#!/usr/bin/python3

# Copyright 2018, Red Hat, Inc.
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
#     http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.

from __future__ import absolute_import, division, print_function
__metaclass__ = type

from ansible.module_utils.basic import AnsibleModule
import datetime
import json
import os
import struct
import time
import base64
import socket


ANSIBLE_METADATA = {
    'metadata_version': '1.1',
    'status': ['preview'],
    'supported_by': 'community'
}

DOCUMENTATION = '''
---
module: ceph_key

author: Sebastien Han <seb@redhat.com>

short_description: Manage Cephx key(s)

version_added: "2.6"

description:
    - Manage CephX creation, deletion and updates.
    It can also list and get information about keyring(s).
options:
    cluster:
        description:
            - The ceph cluster name.
        required: false
        default: ceph
    name:
        description:
            - name of the CephX key
        required: true
    user:
        description:
            - entity used to perform operation.
            It corresponds to the -n option (--name)
        required: false
    user_key:
        description:
            - the path to the keyring corresponding to the
            user being used.
            It corresponds to the -k option (--keyring)
    state:
        description:
            - If 'present' is used, the module creates a keyring
            with the associated capabilities.
            If 'present' is used and a secret is provided the module
            will always add the key. Which means it will update
            the keyring if the secret changes, the same goes for
            the capabilities.
            If 'absent' is used, the module will simply delete the keyring.
            If 'list' is used, the module will list all the keys and will
            return a json output.
            If 'info' is used, the module will return in a json format the
            description of a given keyring.
        required: false
        choices: ['present', 'update', 'absent', 'list', 'info', 'fetch_initial_keys']
        default: present
    caps:
        description:
            - CephX key capabilities
        default: None
        required: false
    secret:
        description:
            - keyring's secret value
        required: false
        default: None
    import_key:
        description:
            - Wether or not to import the created keyring into Ceph.
            This can be useful for someone that only wants to generate keyrings
            but not add them into Ceph.
        required: false
        default: True
    dest:
        description:
            - Destination to write the keyring, can a file or a directory
        required: false
        default: /etc/ceph/
    fetch_initial_keys:
        description:
            - Fetch client.admin and bootstrap key.
            This is only needed for Nautilus and above.
            Writes down to the filesystem the initial keys generated by the monitor.  # noqa E501
            This command can ONLY run from a monitor node.
        required: false
        default: false
    output_format:
        description:
            - The key output format when retrieving the information of an
            entity.
        required: false
        default: json
'''

EXAMPLES = '''

keys_to_create:
  - { name: client.key, key: "AQAin8tUUK84ExAA/QgBtI7gEMWdmnvKBzlXdQ==", caps: { mon: "allow rwx", mds: "allow *" } , mode: "0600" } # noqa e501
  - { name: client.cle, caps: { mon: "allow r", osd: "allow *" } , mode: "0600" } # noqa e501

caps:
  mon: "allow rwx"
  mds: "allow *"

- name: create ceph admin key
  ceph_key:
    name: client.admin
    state: present
    secret: AQAin8tU2DsKFBAAFIAzVTzkL3+gtAjjpQiomw==
    caps:
      mon: allow *
      osd: allow *
      mgr: allow *
      mds: allow
    mode: 0400
    import_key: False

- name: create monitor initial keyring
  ceph_key:
    name: mon.
    state: present
    secret: AQAin8tUMICVFBAALRHNrV0Z4MXupRw4v9JQ6Q==
    caps:
      mon: allow *
    dest: "/var/lib/ceph/tmp/"
    import_key: False

- name: create cephx key
  ceph_key:
    name: "{{ keys_to_create }}"
    user: client.bootstrap-rgw
    user_key: /var/lib/ceph/bootstrap-rgw/ceph.keyring
    state: present
    caps: "{{ caps }}"

- name: create cephx key but don't import it in Ceph
  ceph_key:
    name: "{{ keys_to_create }}"
    state: present
    caps: "{{ caps }}"
    import_key: False

- name: delete cephx key
  ceph_key:
    name: "my_key"
    state: absent

- name: info cephx key
  ceph_key:
    name: "my_key""
    state: info

- name: info cephx admin key (plain)
  ceph_key:
    name: client.admin
    output_format: plain
    state: info
  register: client_admin_key

- name: list cephx keys
  ceph_key:
    state: list

- name: fetch cephx keys
  ceph_key:
    state: fetch_initial_keys
'''

RETURN = '''#  '''


CEPH_INITIAL_KEYS = ['client.admin', 'client.bootstrap-mds', 'client.bootstrap-mgr',  # noqa E501
                     'client.bootstrap-osd', 'client.bootstrap-rbd', 'client.bootstrap-rbd-mirror', 'client.bootstrap-rgw']  # noqa E501


def str_to_bool(val):
    try:
        val = val.lower()
    except AttributeError:
        val = str(val).lower()
    if val == 'true':
        return True
    elif val == 'false':
        return False
    else:
        raise ValueError("Invalid input value: %s" % val)


def fatal(message, module):
    '''
    Report a fatal error and exit
    '''

    if module:
        module.fail_json(msg=message, rc=1)
    else:
        raise(Exception(message))


def container_exec(binary, container_image):
    '''
    Build the docker CLI to run a command inside a container
    '''

    container_binary = os.getenv('CEPH_CONTAINER_BINARY')
    command_exec = [container_binary,
                    'run',
                    '--rm',
                    '--net=host',
                    '-v', '/etc/ceph:/etc/ceph:z',
                    '-v', '/var/lib/ceph/:/var/lib/ceph/:z',
                    '-v', '/var/log/ceph/:/var/log/ceph/:z',
                    '--entrypoint=' + binary, container_image]
    return command_exec


def is_containerized():
    '''
    Check if we are running on a containerized cluster
    '''

    if 'CEPH_CONTAINER_IMAGE' in os.environ:
        container_image = os.getenv('CEPH_CONTAINER_IMAGE')
    else:
        container_image = None

    return container_image


def generate_secret():
    '''
    Generate a CephX secret
    '''

    key = os.urandom(16)
    header = struct.pack('<hiih', 1, int(time.time()), 0, len(key))
    secret = base64.b64encode(header + key)

    return secret


def generate_caps(_type, caps):
    '''
    Generate CephX capabilities list
    '''

    caps_cli = []

    for k, v in caps.items():
        # makes sure someone didn't pass an empty var,
        # we don't want to add an empty cap
        if len(k) == 0:
            continue
        if _type == "ceph-authtool":
            caps_cli.extend(["--cap"])
        caps_cli.extend([k, v])

    return caps_cli


def generate_ceph_cmd(cluster, args, user, user_key_path, container_image=None):
    '''
    Generate 'ceph' command line to execute
    '''

    if container_image:
        binary = 'ceph'
        cmd = container_exec(
            binary, container_image)
    else:
        binary = ['ceph']
        cmd = binary

    base_cmd = [
        '-n',
        user,
        '-k',
        user_key_path,
        '--cluster',
        cluster,
        'auth',
    ]

    cmd.extend(base_cmd + args)

    return cmd


def generate_ceph_authtool_cmd(cluster, name, secret, caps, dest, container_image=None):  # noqa E501
    '''
    Generate 'ceph-authtool' command line to execute
    '''

    if container_image:
        binary = 'ceph-authtool'
        cmd = container_exec(
            binary, container_image)
    else:
        binary = ['ceph-authtool']
        cmd = binary

    base_cmd = [
        '--create-keyring',
        dest,
        '--name',
        name,
        '--add-key',
        secret,
    ]

    cmd.extend(base_cmd)
    cmd.extend(generate_caps("ceph-authtool", caps))

    return cmd


def create_key(module, result, cluster, user, user_key_path, name, secret, caps, import_key, dest, container_image=None):  # noqa E501
    '''
    Create a CephX key
    '''

    cmd_list = []
    if not secret:
        secret = generate_secret()

    if user == 'client.admin':
        args = ['import', '-i', dest]
    else:
        args = ['get-or-create', name]
        args.extend(generate_caps(None, caps))
        args.extend(['-o', dest])

    cmd_list.append(generate_ceph_authtool_cmd(
        cluster, name, secret, caps, dest, container_image))

    if import_key or user != 'client.admin':
        cmd_list.append(generate_ceph_cmd(
            cluster, args, user, user_key_path, container_image))

    return cmd_list


def delete_key(cluster, user, user_key_path, name, container_image=None):
    '''
    Delete a CephX key
    '''

    cmd_list = []

    args = [
        'del',
        name,
    ]

    cmd_list.append(generate_ceph_cmd(
        cluster, args, user, user_key_path, container_image))

    return cmd_list


def get_key(cluster, user, user_key_path, name, dest, container_image=None):
    '''
    Get a CephX key (write on the filesystem)
    '''

    cmd_list = []

    args = [
        'get',
        name,
        '-o',
        dest,
    ]

    cmd_list.append(generate_ceph_cmd(
        cluster, args, user, user_key_path, container_image))

    return cmd_list


def info_key(cluster, name, user, user_key_path, output_format, container_image=None):  # noqa E501
    '''
    Get information about a CephX key
    '''

    cmd_list = []

    args = [
        'get',
        name,
        '-f',
        output_format,
    ]

    cmd_list.append(generate_ceph_cmd(
        cluster, args, user, user_key_path, container_image))

    return cmd_list


def list_keys(cluster, user, user_key_path, container_image=None):
    '''
    List all CephX keys
    '''

    cmd_list = []

    args = [
        'ls',
        '-f',
        'json',
    ]

    cmd_list.append(generate_ceph_cmd(
        cluster, args, user, user_key_path, container_image))

    return cmd_list


def exec_commands(module, cmd_list):
    '''
    Execute command(s)
    '''

    for cmd in cmd_list:
        rc, out, err = module.run_command(cmd)
        if rc != 0:
            return rc, cmd, out, err

    return rc, cmd, out, err


def lookup_ceph_initial_entities(module, out):
    '''
    Lookup Ceph initial keys entries in the auth map
    '''

    # convert out to json, ansible returns a string...
    try:
        out_dict = json.loads(out)
    except ValueError as e:
        fatal("Could not decode 'ceph auth list' json output: {}".format(e), module)  # noqa E501

    entities = []
    if "auth_dump" in out_dict:
        for key in out_dict["auth_dump"]:
            for k, v in key.items():
                if k == "entity":
                    if v in CEPH_INITIAL_KEYS:
                        entities.append(v)
    else:
        fatal("'auth_dump' key not present in json output:", module)  # noqa E501

    if len(entities) != len(CEPH_INITIAL_KEYS) and not str_to_bool(os.environ.get('CEPH_ROLLING_UPDATE', False)):  # noqa E501
        # must be missing in auth_dump, as if it were in CEPH_INITIAL_KEYS
        # it'd be in entities from the above test. Report what's missing.
        missing = []
        for e in CEPH_INITIAL_KEYS:
            if e not in entities:
                missing.append(e)
        fatal("initial keyring does not contain keys: " + ' '.join(missing), module)  # noqa E501
    return entities


def build_key_path(cluster, entity):
    '''
    Build key path depending on the key type
    '''

    if "admin" in entity:
        path = "/etc/ceph"
        keyring_filename = cluster + "." + entity + ".keyring"
        key_path = os.path.join(path, keyring_filename)
    elif "bootstrap" in entity:
        path = "/var/lib/ceph"
        # bootstrap keys show up as 'client.boostrap-osd'
        # however the directory is called '/var/lib/ceph/bootstrap-osd'
        # so we need to substring 'client.'
        entity_split = entity.split('.')[1]
        keyring_filename = cluster + ".keyring"
        key_path = os.path.join(path, entity_split, keyring_filename)
    else:
        return None

    return key_path


def run_module():
    module_args = dict(
        cluster=dict(type='str', required=False, default='ceph'),
        name=dict(type='str', required=False),
        state=dict(type='str', required=False, default='present', choices=['present', 'update', 'absent', 'list', 'info', 'fetch_initial_keys']),
        caps=dict(type='dict', required=False, default=None),
        secret=dict(type='str', required=False, default=None, no_log=True),
        import_key=dict(type='bool', required=False, default=True),
        dest=dict(type='str', required=False, default='/etc/ceph/'),
        user=dict(type='str', required=False, default='client.admin'),
        user_key=dict(type='str', required=False, default=None),
        output_format=dict(type='str', required=False, default='json', choices=['json', 'plain', 'xml', 'yaml'])
    )

    module = AnsibleModule(
        argument_spec=module_args,
        supports_check_mode=True,
        add_file_common_args=True,
    )

    file_args = module.load_file_common_arguments(module.params)

    # Gather module parameters in variables
    state = module.params['state']
    name = module.params.get('name')
    cluster = module.params.get('cluster')
    caps = module.params.get('caps')
    secret = module.params.get('secret')
    import_key = module.params.get('import_key')
    dest = module.params.get('dest')
    user = module.params.get('user')
    user_key = module.params.get('user_key')
    output_format = module.params.get('output_format')

    changed = False

    result = dict(
        changed=changed,
        stdout='',
        stderr='',
        rc=0,
        start='',
        end='',
        delta='',
    )

    if module.check_mode:
        module.exit_json(**result)

    startd = datetime.datetime.now()

    # will return either the image name or None
    container_image = is_containerized()

    # Test if the key exists, if it does we skip its creation
    # We only want to run this check when a key needs to be added
    # There is no guarantee that any cluster is running and we don't need one
    _secret = secret
    _caps = caps
    key_exist = 1

    if not user_key:
        user_key_filename = '{}.{}.keyring'.format(cluster, user)
        user_key_dir = '/etc/ceph'
        user_key_path = os.path.join(user_key_dir, user_key_filename)
    else:
        user_key_path = user_key

    if (state in ["present", "update"]):
        # if dest is not a directory, the user wants to change the file's name
        # (e,g: /etc/ceph/ceph.mgr.ceph-mon2.keyring)
        if not os.path.isdir(dest):
            file_path = dest
        else:
            if 'bootstrap' in dest:
                # Build a different path for bootstrap keys as there are stored
                # as /var/lib/ceph/bootstrap-rbd/ceph.keyring
                keyring_filename = cluster + '.keyring'
            else:
                keyring_filename = cluster + "." + name + ".keyring"
            file_path = os.path.join(dest, keyring_filename)

        file_args['path'] = file_path

        if import_key:
            _info_key = []
            rc, cmd, out, err = exec_commands(
                module, info_key(cluster, name, user, user_key_path, output_format, container_image))  # noqa E501
            key_exist = rc
            if not caps and key_exist != 0:
                fatal("Capabilities must be provided when state is 'present'", module)  # noqa E501
            if key_exist != 0 and secret is None and caps is None:
                fatal("Keyring doesn't exist, you must provide 'secret' and 'caps'", module)  # noqa E501
            if key_exist == 0:
                _info_key = json.loads(out)
                if not secret:
                    secret = _info_key[0]['key']
                _secret = _info_key[0]['key']
                if not caps:
                    caps = _info_key[0]['caps']
                _caps = _info_key[0]['caps']
                if secret == _secret and caps == _caps:
                    if not os.path.isfile(file_path):
                        rc, cmd, out, err = exec_commands(module, get_key(cluster, user, user_key_path, name, file_path, container_image))  # noqa E501
                        result["rc"] = rc
                        if rc != 0:
                            result["stdout"] = "Couldn't fetch the key {0} at {1}.".format(name, file_path) # noqa E501
                            module.exit_json(**result)
                        result["stdout"] = "fetched the key {0} at {1}.".format(name, file_path) # noqa E501

                    result["stdout"] = "{0} already exists and doesn't need to be updated.".format(name) # noqa E501
                    result["rc"] = 0
                    module.set_fs_attributes_if_different(file_args, False)
                    module.exit_json(**result)
        else:
            if os.path.isfile(file_path) and not secret or not caps:
                result["stdout"] = "{0} already exists in {1} you must provide secret *and* caps when import_key is {2}".format(name, dest, import_key) # noqa E501
                result["rc"] = 0
                module.exit_json(**result)
        if (key_exist == 0 and (secret != _secret or caps != _caps)) or key_exist != 0:  # noqa E501
            rc, cmd, out, err = exec_commands(module, create_key(
                module, result, cluster, user, user_key_path, name, secret, caps, import_key, file_path, container_image))  # noqa E501
            if rc != 0:
                result["stdout"] = "Couldn't create or update {0}".format(name)
                result["stderr"] = err
                module.exit_json(**result)
            module.set_fs_attributes_if_different(file_args, False)
            changed = True

    elif state == "absent":
        if key_exist == 0:
            rc, cmd, out, err = exec_commands(
                module, delete_key(cluster, user, user_key_path, name, container_image))
            if rc == 0:
                changed = True
        else:
            rc = 0

    elif state == "info":
        rc, cmd, out, err = exec_commands(
            module, info_key(cluster, name, user, user_key_path, output_format, container_image))  # noqa E501
        if rc != 0:
            result["stdout"] = "skipped, since {0} does not exist".format(name)
            result['rc'] = 0
            module.exit_json(**result)

    elif state == "list":
        rc, cmd, out, err = exec_commands(
            module, list_keys(cluster, user, user_key_path, container_image))

    elif state == "fetch_initial_keys":
        hostname = socket.gethostname().split('.', 1)[0]
        user = "mon."
        keyring_filename = cluster + "-" + hostname + "/keyring"
        user_key_path = os.path.join("/var/lib/ceph/mon/", keyring_filename)
        rc, cmd, out, err = exec_commands(
            module, list_keys(cluster, user, user_key_path, container_image))
        if rc != 0:
            result["stdout"] = "failed to retrieve ceph keys"
            result["sdterr"] = err
            result['rc'] = 0
            module.exit_json(**result)

        entities = lookup_ceph_initial_entities(module, out)

        output_format = "plain"
        for entity in entities:
            key_path = build_key_path(cluster, entity)
            if key_path is None:
                fatal("Failed to build key path, no entity yet?", module)
            elif os.path.isfile(key_path):
                # if the key is already on the filesystem
                # there is no need to fetch it again
                continue

            extra_args = [
                '-o',
                key_path,
            ]

            info_cmd = info_key(cluster, entity, user,
                                user_key_path, output_format, container_image)
            # we use info_cmd[0] because info_cmd is an array made of an array
            info_cmd[0].extend(extra_args)
            rc, cmd, out, err = exec_commands(
                module, info_cmd)  # noqa E501

            file_args = module.load_file_common_arguments(module.params)
            file_args['path'] = key_path
            module.set_fs_attributes_if_different(file_args, False)
    else:
        module.fail_json(
            msg='State must either be "present" or "absent" or "list" or "info" or "fetch_initial_keys".', changed=False, rc=1)  # noqa E501

    endd = datetime.datetime.now()
    delta = endd - startd

    result = dict(
        cmd=cmd,
        start=str(startd),
        end=str(endd),
        delta=str(delta),
        rc=rc,
        stdout=out.rstrip("\r\n"),
        stderr=err.rstrip("\r\n"),
        changed=changed,
    )

    if rc != 0:
        module.fail_json(msg='non-zero return code', **result)

    module.exit_json(**result)


def main():
    run_module()


if __name__ == '__main__':
    main()